In the oil and gas industry, production well-testing at oil and gas wellheads is performed to quantify the amount of water, oil and gas produced from an individual well. This information is important as it allows the parameters of oil production to be adjusted in order to maximize the efficiency of the production well. Conventional well testing technologies, such as Test Separators and Dean Stark extraction, generally involve the use of large scale and expensive equipment that is time-consuming to use and that, as a result of the complexity of the equipment, often leads to delays during well production. Alternative metering technologies, such as Nuclear Magnetic Resonance (NMR), Microwaves, and Gamma Ray based meters, are becoming increasingly available and generally have the potential to offer savings in terms of time, space, and cost in comparison to conventional well testing technologies. In addition, these alternative metering technologies typically have the capability to be more reliable and accurate compared to conventional well testing technologies. A magnetic resonance apparatus is described in U.S. Pat. No. 4,350,955.
In general, conventional pipes used to convey hydrocarbon fluids from wells have a metallic component to them. Metallic pipes are known to create problems for certain alternative metering technologies, such as nuclear magnetic resonance (NMR) meters. NMR meters function by applying an external static magnetic and a pulsating electromagnetic field to a sample to determine the components of the sample in terms of water, oil and gas content. Such systems are described in US Patent Publication No. 2009/0128144; US Patent Publication No. 2009/0072825; U.S. Pat. No. 6,346,813; U.S. Pat. No. 7,463,027; US Patent Publication No. 2010/0001730; and U.S. Pat. No. 6,825,657. As NMR meters use magnetic fields, metallic materials located near NMR meters will serve as transmitters and undermine the accuracy and sensitivity of the NMR meter. As such, there is generally a need for systems that mitigate these problems, and more specifically there has been a need for improved pipe designs that can be used with an NMR metering tool to increase the accuracy and sensitivity of an NMR meter in the field.
In addition, the oil and gas industry generally operates in a high pressure, temperature and corrosive environment where process fluids are typically comprised of hydrocarbons, hydrogen sulfide, water, steam, carbon dioxide and inert substances such as nitrogen gas and sand particles. As is known, high temperatures and pressures are routinely encountered in a production well, with temperatures reaching 533 K (260° C.; 500° F.) and pressures reaching 4136 kPa (600 Psi). Thus, in the context of alternate metering technologies, including NMR equipment, there continues to be a need for effective apparatus for containing a fluid sample at well head that can withstand the corrosive environment of oil and gas wells as well as the high temperatures and pressures of oil and gas wells while also enabling effective alternative metering technologies.
A review of the prior art indicates that such systems and particularly NMR systems have not been developed. For example, U.S. Pat. No. 7,053,611; U.S. Pat. No. 7,091,719; U.S. Pat. No. 6,952,096 and US Patent Publication No. 2007/0222444 describe methods for determining fluid properties in formations using NMR instruments.
As a result, there continues to be a need for well-testing equipment and methodologies, particularly for NMR instruments, that improve the effectiveness of NMR measurements in both stationary and moving fluids and can be performed in a short period of time in the field.